[1] The causes of renewed growth in the atmospheric CH 4 burden since 2007 are still poorly understood and subject of intensive scientific discussion. We present a reanalysis of global CH 4 emissions during the 2000s, based on the TM5-4DVAR inverse modeling system. The model is optimized using high-accuracy surface observations from NOAA ESRL's global air sampling network for 2000-2010 combined with retrievals of column-averaged CH 4 mole fractions from SCIAMACHY onboard ENVISAT (starting 2003). Using climatological OH fields, derived global total emissions for 2007-2010 are 16-20 Tg CH 4 /yr higher compared to [2003][2004][2005]. Most of the inferred emission increase was located in the tropics (9-14 Tg CH 4 /yr) and mid-latitudes of the northern hemisphere (6-8 Tg CH 4 /yr), while no significant trend was derived for Arctic latitudes. The atmospheric increase can be attributed mainly to increased anthropogenic emissions, but the derived trend is significantly smaller than estimated in the EDGARv4.2 emission inventory. Superimposed on the increasing trend in anthropogenic CH 4 emissions are significant inter-annual variations (IAV) of emissions from wetlands (up to AE10 Tg CH 4 /yr), and biomass burning (up to AE7 Tg CH 4 /yr). Sensitivity experiments, which investigated the impact of the SCIAMACHY observations (versus inversions using only surface observations), of the OH fields used, and of a priori emission inventories, resulted in differences in the detailed latitudinal attribution of CH 4 emissions, but the IAV and trends aggregated over larger latitude bands were reasonably robust. All sensitivity experiments show similar performance against independent shipboard and airborne observations used for validation, except over Amazonia where satellite retrievals improved agreement with observations in the free troposphere. Citation: Bergamaschi, P., et al. (2013), Atmospheric CH 4 in the first decade of the 21st century: Inverse modeling analysis using SCIAMACHY satellite retrievals and NOAA surface measurements,

Abstract. Atmospheric gaseous sulphuric acid was measured and its influence on particle formation and growth was investigated building on aerosol data. The measurements were part of the EU-project QUEST and took place at two different measurement sites in Northern and Central Europe (Hyytiälä, Finland, March-April 2003 and Heidelberg, Germany, March-April 2004). From a comprehensive data set including sulphuric acid, particle number size distributions and meteorological data, particle growth rates, particle formation rates and source rates of condensable vapors were inferred. Growth rates were determined in two different ways, from particle size distributions as well as from a so-called timeshift analysis. Moreover, correlations between sulphuric acid and particle number concentration between 3 and 6 nm were examined and the influence of air masses of different origin was investigated. Measured maximum concentrations of sulphuric acid were in the range from 1×10 6 to 16×10 6 cm −3 . The gaseous sulphuric acid lifetime with respect to condensation on aerosol particles ranged from 2 to 33 min in Hyytiälä and from 0.5 to 8 min in Heidelberg. Most calculated values (growth rates, formation rates, vapor source rates) were considerably higher in Central Europe (Heidelberg), due to the more polluted air and higher preexistent aerosol concentrations. Close correlations between H 2 SO 4 and nucleation mode particles (size range: 3-6 nm) were found on most days at both sites. The percentage contribution of sulphuric acid to particle growth was below 10% at both places and to initial growth below 20%. An air mass analysis indicated that at Heidelberg new particles were formed predominantly in air advected from southwesterly directions.

[1] Estimates of surface fluxes of carbon monoxide (CO) inferred from remote sensing observations or free tropospheric trace gas measurements using global chemical transport models can have significant uncertainties because of discrepancies in the vertical transport in the models, which make it challenging to unequivocally relate the observations back to the surface fluxes in the models. The new Measurement of Pollution in the Troposphere (MOPITT) version 5 retrievals provide greater sensitivity to lower tropospheric CO over land relative to the previous versions and are, therefore, useful for evaluating vertical transport in models. We have assimilated the new MOPITT CO retrievals, using the Goddard Earth Observing System (GEOS)-Chem model, to study the influence of vertical transport errors on inferred CO sources. We compared the source estimates obtained by assimilating the CO profiles, the column amounts, and the surface level retrievals for June-August 2006. The three different inversions produced large differences in the source estimates in regions of convection and strong CO emissions. The inversion using the CO profiles suggested an 85% increase in emissions in India/Southeast Asia, which exacerbated the model bias in the lower and middle troposphere, whereas using the surface level retrievals produced a 37% decrease in Indian/Southeast Asian emissions, which exacerbated the underestimate of CO in the upper troposphere. Globally, the inversion with the surface retrievals suggested a 22% reduction in emissions from the a priori estimate of 161 Tg CO/month (from combustion and the oxidation of biogenic volatile organic compounds), averaged in June-August 2006. The analysis results were validated with independent surface CO measurements from NOAA Global Monitoring Division (GMD) network and upper troposphere CO measurements from the Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrumented Container (CARIBIC). We found that the inversion with the surface retrievals agreed best with surface CO data but produced the largest discrepancy with the CARIBIC aircraft data in the upper troposphere, suggesting the influence of vertical transport errors in the model. Our results show that the comparison of the a posteriori CO distributions obtained from the inversions using the surface and profile retrievals provides a means of characterizing the potential impact of the vertical transport biases on the source estimates and the CO distribution.

[1] Because very few measurements of atmospheric carbon dioxide (CO 2 ) are available in the tropics, estimates of surface CO 2 fluxes in tropical regions are beset with considerable uncertainties. To improve estimates of tropical terrestrial fluxes, atmospheric CO 2 inversion was performed using passenger aircraft based measurements of the Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL) project in addition to the surface measurement data set of GLOBALVIEW-CO 2 . Regional monthly fluxes at the earth's surface were estimated using the Bayesian synthesis approach focusing on the period 2006-2008 using the Nonhydrostatic Icosahedral Atmospheric Model-based Transport Model (NICAM-TM). By adding the aircraft to the surface data, the posterior flux errors were greatly reduced; specifically, error reductions of up to 64% were found for tropical Asia regions. This strong impact is closely related to efficient vertical transport in the tropics. The optimized surface fluxes using the CONTRAIL data were evaluated by comparing the simulated atmospheric CO 2 distributions with independent aircraft measurements of the Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container (CARIBIC) project. The inversion with the CONTRAIL data yields the global carbon sequestration rates of 2.22 AE 0.28 Pg C yr À1 for the terrestrial biosphere and 2.24 AE 0.27 Pg C yr À1 for the oceans (the both are adjusted by riverine input of CO 2 ). For the first time the CONTRAIL CO 2 measurements were used in an inversion system to identify the areas of greatest impact in terms of reducing flux uncertainties.

Abstract. The production of K + and of K − mesons in heavy-ion collisions at beam energies of 1 to 2 AGeV has systematically been investigated with the Kaon Spectrometer KaoS. The ratio of the K + production excitation function for Au+Au and for C+C reactions increases with decreasing beam energy, which is expected for a soft nuclear equation-of-state. A comprehensive study of the K + and of the K − emission as a function of the size of the collision system, of the collision centrality, of the kaon energy, and of the polar emission angle has been performed. The K − /K + ratio is found to be nearly constant as a function of the collision centrality and can be explained by the dominance of strangeness exchange. On the other hand the spectral slopes and the polar emission patterns are different for K − and for K + . Furthermore the azimuthal distribution of the particle emission has been investigated. K + mesons and pions are emitted preferentially perpendicular to the reaction plane as well in Au+Au as in Ni+Ni collisions. In contrast for K − mesons in Ni+Ni reactions an in-plane flow was observed for the first time at these incident enegies.